The present invention relates generally to prosthetic eyes. More particularly, it relates to a prosthetic eye with a pupil that can dilate when used with a polarized lens.
After injury or disease, a patient may need to have his or her natural eye removed. There are many ocular prosthetic devices that simulate the appearance of a natural eye and attempt to faithfully reproduce the physical features of the natural eye. Often such prosthetic eyes have a simulated iris of a color and pattern so as to match the complementary natural eye and a simulated pupil. The iris image is produced on a white prosthetic shell adapted to be covered with a clear medium. The simulated pupil is of a fixed size and does not react to light intensity, thereby detracting from the appearance of a natural eye. Attempts have been made to simulate a pupil that adjusts to light level so as to provide an appearance of pupil dilation and contraction in response to ambient light. However, these are often complicated, and therefore expensive devices, and may require frequent maintenance or replacement to maintain their desired appearance.
The present invention takes the form of a prosthetic eye and a coordinating pair of glasses. The prosthetic eye is formed of a material such as polymethyl-methacrylate and has a globular scleral portion colored white to simulate a human eye. In the place of the normal iris of the eye, a simulated iris is painted on the front of the scleral portion to match the user""s natural eye color. A polarized disc is located at the center of the iris. The polarized disc is placed on the horizontal transmitting axis (180 degrees). The center of the front surface of the polarized disc is darkened with paint to simulate a pupil having a fairly small diameter. The back of the polarized disc is painted to blend with the iris or simulate the collarette of the eye. Over the top of the polarized disc and iris is a dome of material simulating the cornea of the eye.
The polarized disc in the prosthetic eye is used in conjunction with the special application of a polarized lens, thereby making the pupil of the eye prosthesis appear to dilate because it causes the entire disc to blacken when viewed through the polarized lens. The lens that is needed to xe2x80x9cdilatexe2x80x9d the pupil is formed of linearly polarizing material that has been incorporated into the patient""s eyeglasses with the transmitting axis in the vertical (90 degree) plane. Wearing the eyeglasses creates the interference between the two polarized lenses, thereby creating a larger darkened area simulating dilation of the pupil. Conversely, removal of the glasses causes it to lighten, showing the details painted on the back of the disc, thereby making the pupil appear smaller in diameter.